Aw, yay! I LOVE this story, thankyou for reminding me of it. The bit about Mulder looking like a special agent of porn makes me laugh out loud every time I read it.

Also, testament to the quality of the writing, I can totally visualise this story as if it were filmed as an episode. And what a GREAT episode it would have made! They would have had to leave the showering bits out, I imagine, to satisfy the censors, but it would still have been hilarious. Like someone said in comments to the OP, DD and GA would have been great acting as a body-swapped Mulder and Scully. Can you imagine? Oh man, I wish this had been an episode.